The NBA made a mistake when it told the Kentucky freshman, Nerlens Noel, he couldn't be a pro this season.

The league, instead, should have been able to tell him he also couldn't be a pro next season.

But a year ago, the NBA failed to collectively bargain an extended age limit, undercutting the business of pro basketball, and this is what the blame should be about.

Not a teenager's injury.

Steve Kerr has been advocating the change in the age limit for a while. He wrote a piece last spring for ESPN.com, pushing for what in effect would be a two-year wait for a graduating high school senior.

“Fans and critics have assorted opinions about morals, ethics, education, fairness, and law,” Kerr wrote. “But to me, this really comes down to a single issue: Would the NBA's business be stronger by raising the age requirement?”

No one likes the world of one-and-done, and college campuses suffer more from it. Programs are as splintered as the integrity of academia.

Compared to that, an additional year would simply be more efficient to the NBA. Scouts would have a better sense of the talent they are trying to judge, and franchises could better market more recognizable names.

As for the maturity factor: While Kerr admits LeBron James and Kobe Bryant are among those who survived without college, he also thinks both would have benefited by growing up in a college locker room.

But few wanted to hear that Wednesday. Then, Noel was diagnosed with an ACL tear, and someone projected to be the No. 1 pick in this year's draft likely lost some money.

“If this injury compromises Noel's draft status,” a Yahoo.com columnist wrote, “it's on David Stern and his league's minimum age requirement.”

Kerr, on Wednesday, said he understands the sentiment. He's seen Noel play, and he said he looks like “a baby giraffe.”

Who could root against that image? And when Noel collapsed Tuesday night, the image in front of 12,480 silent fans was haunting.

“All you could hear,” a Sporting News columnist wrote, “was an 18-year-old screaming in pain.”

Sixteen NBA scouts who were there heard it, too. And with that, Noel became a 6-foot-10 symbol of a system where everyone makes money except the kid who is risking his future earnings.

But is that on Stern? As Kerr said, it's not the NBA's “responsibility” to provide jobs for teenagers. It's about running a business, and it's not arbitrary or unlawful. The league and the players' union collectively bargain the terms of employment.

It spreads beyond basketball. Football players have to be three years removed from high school to be draft eligible, and Jadeveon Clowney of South Carolina feels this now.

He would probably be the top NFL draft pick this spring, but he faces another year of a more violent sport. That's why some wonder if the smarter financial decision would be for him to simply sit out next season.

Noel doesn't have to sit out. If he chooses to leave school, an NBA team will still draft him this June, maybe even in the top five. Given that, maybe he will opt to rehab with NBA professionals.

Stern would prefer something else. He's on the record saying he would like to add another year.

So why didn't it happen? The issue was just one of many during the lockout, and it was overshadowed by more substantial financial compromises. With the season in jeopardy, the age limit fell through the cracks.

Now the NBA is stuck, and teenagers are told they have to wait one year to become eligible.